Carbonylated aliphatic polymers



United States Patent 3,417,020 CARBONYLATED ALIPHATIC POLYMERS Albert F.Preuss, Willow Grove, and Robert Winslow White, Jenkintown, Pa.,assignors to Rohm and Haas Company, Philadelphia, Pa., a corporation ofDelaware N0 Drawing. Original application Apr. 18, 1963, Ser. No.

273,837. Divided and this application Mar. 8, 1967,

Ser. No. 621,411

3 Claims. (Cl. 252-52) ABSTRACT OF THE DISCLOSURE This inventionconcerns oil-soluble aliphatic hydrocarbon polymers having a carbonylgroup, a method for their preparation, and lubricating compositionscontaining them. As olefinic polymers there may be used any of thepolymers formed from olefins containing three to twelve carbon atoms.The process for preparing the oil-soluble saturated aliphatichydrocarbon polymers of this inven tion comprises 1) reacting anolefinic polymer of a molecular weight of about 300 to 5,000 with ozone,the polymer being in a liquid state, whereby an ozonolysis product isformed, and (2) reducing the resulting ozonolysis product until acarbonyl group is formed thereon.

Cross references to related applications This application is a divisionof US. application Serial No. 273,837, filed April 18, 1963 (nowabandoned).

Background of the invention Lubricating oils have been synthesized bypolymerizing olefins, as with aluminum chloride and related catalysts.It has also been proposed to hydrogenate such oils to improve theirstability. Polymers of isobutylene have been prepared and used in oilsto increase viscosity. Such polymers, however, are not fully compatiblewith various synthetic lubricants and tend to depolymerize at hightemperatures.

Detailed description of the invention This invention concernsoil-soluble aliphatic hydrocarbon polymers having a carbonyl group, amethod for their preparation, and lubricating compositions containingthem.

The process for preparing the oil-soluble saturated aliphatichydrocarbon polymers of this invention comprises (l) reacting anolefinic polymer of a molecular weight of about 300 to 5,000 with ozone,the polymer being in a liquid state, whereby an ozonolysis product isformed, and (2) reducing the resulting ozonolysis product until acarbonyl group is formed thereon.

As olefinic polymers there may be used any of the polymers formed fromolefins containing three to twelve carbon atoms, preferably three tofive carbon atoms, by additional polymerization from pure olefins,Whether gaseous or liquid under normal conditions. The usual source ofolefins is from cracking petroleum and other hydrocarbons. Fractionscontaining considerable proportions of olefinically unsaturatedopen-chained hydrocarbons are readily obtained. The importance ofremoval of sulfur, cyclic compounds, and other impurities is wellunderstood. Olefins from propylene upward to dodecene are readilyavailable and mixtures may be used or fractions may be taken forpolymerization. Mixtures of various olefins from propylene to pentenes,for example, may be used or a mixture of the various butenes isespecially useful in providing polymers. As is known, propylene can giveuseful polymers with an increased proportion of catalyst, while pentenesare slower to polymerize than "ice olefins of smaller size. Ethylene maybe utilized as a minor component in conjunction with other olefins, oilypolymers from propylene and ethylene are known, for example. The butenefraction is most commonly employed and comprises both straight-chainedand branched butenes. If desired, polymers may be prepared fromisobu-tylene, but for purposes of this invention such separation orisolation is not essential. Thus, the polybutenes of commerce, derivedfrom mixtures are especially useful. The olefinic polymers used asstarting materials should have molecular weights of about 300 to 5,000for purposes of this invention. They vary from rather fluid liquids toquite viscous liquids at normal temperatures.

Ozonolysis of a polyolefin or a mixture of polyolefins is effected bybringing ozone in contact with polyolefin in a liquid state. Ozone isusually supplied diluted with oxygen or air. Since the polyolefins tendto be viscous, it is desirable to extend them with one or more solventswhich are inert to ozone under the conditions of reaction.

Typical solvents include liquid aliphatic hydrocarbons, such as hexane,heptane, octane, mixture of alkanes, petroleum ethers, benzenes,toluene, xylene, aromatic naphthas, chlorinated hydrocarbons such asdichloroethane, tetrachloroethane, trichloroethane, carbontetrachloride, or trichloropropane, esters such as ethyl or butylacetate, ethyl propionate, dibutyl sebacate, di-Z-ethylhexyl sebacate,di-n-octyl azelate or pimelate, or dinonyl pimelate, azelate, orsebacate.

In a particularly elfective system for reacting polyolefin and ozone aliquid alcohol may be used. Desirably there is present at least one moleof alcohol per mole of polyolefin, for an alcohol reacts with theozonolysis product and aids in the reaction. Useful alcohols includemethyl, ethyl, propyl, isopropyl, butyl, hexyl, and octyl alcohols aswell as mixtures of alcohols.

Reaction of olefin and ozone is effected between C. and 60 C.,preferably between about 30 C. and 30 C. Ozone is supplied until atleast 10%, preferably 25%, of the olefinic linkages of the polyolefinshave been reacted and reaction may be continued until one mole of ozonehas been used per mole of polymer.

It is not necessary to isolate the ozonolysis products, although thismay be done if desided. Also, if desired, the progress of the reactionmay be followed by determination of peroxide.

After ozonolysis has been effected, the resulting product is reduced.Chemical reduction may be employed, as with nascent hydrogen or with areducing agent such as stannous chloride, titanium trichloride, sulfurdioxide, a bisulfite or hydrosulfite. Nascent hydrogen may be suppliedby reaction of acid on a metal such as zinc or iron. Also, preferablyhydrogen may be used in the presence of a hydrogenation catalyst, suchas platinum, palladium, or activated nickel.

Hydrogen is supplied until about one mole of hydrogen is consumed permole of polyolefin. Temperature of hydrogenation may vary from about 0C. to C. depending upon the catalyst. Pressures may vary fromatmospheric to 500 lbs. per square inch or more. Hydrogenation of theozonolysis product is best accomplished in the presence of a solvent.

Catalyst is separated from the reaction mixture and solvent may bevolatilized therefrom by heating. If desired, the product may be takenup in an oil or synthetic lubricant which is conveniently added beforeremoval of volatile materials. In this way concentrated solutions ofproduct in oil or other lubricants are readily prepared. Also, thisprocedure provides a simple way to transfer a desired amount ofcarbonylated product to any lubricating composition.

Further details of preparation and use are given in the followingexamples which are presented for purposes f illustration and not by wayof limitation. Parts are by eight unless otherwise designated.

Example 1 (a) A solution is prepared from 200 parts of hexane and 42parts of a polyolefin having a molecular weight f 800 and prepared froma mixture of olefins which are chiefly l-butene and isobutylene. Astream of oxygen containing ozone is passed into the solution at aboutroom temperature (25 C.) for 76 minutes. The stream supplied 0.69millimole of ozone per minute. There results a solution of ozonolyzedpolyolefin.

When a sample of this solution is heated, solvent is vaporized to givean oily residue. This is heated at 65 to 70 C. to decompose peroxideswhich may be present. The resulting product has an acidity of 0.118milliquivalent per gram.

(b) The bulk of the above solution of ozonolyzed product is mixed withone part of platinum dioxide and cooled to about 45 C. Hydrogen isadmitted and the reaction mixture changes in temperature to about C.Hydrogen is vented, catalyst is filtered off, and solvent I isevaporated under reduced pressure to give a residue. Examination of thisby infrared absorption shows the presence of a carbonyl group. Theresidue is soluble in lubricating oils and in synthetic lubricants suchas di-2- ethyl-hexyl sebacate. The residue at room temperature is aviscous liquid.

Example 2 (a) There are mixed 150 parts (0.125 mole) of a commercialpolybutene of a molecular weight of about 1200, 300 parts of n-butanol,and 300 parts of n-hexane. The mixture is cooled to about 10 C. and astream of oxygen-containing ozone is passed therethrough at the rate of1.45 millimoles of ozone per minute for 86 minutes.

(b) The resulting solution is treated with about one part of platinumand cooled to -50 C. Hydrogen is passed into the mixture while thetemperature thereof rises to about 0 C. About 0.12 mole of hydrogen isabsorbed. Catalyst is filtered from the treated solution, which is thenheated to 75 C. under reduced pressure, which is finally lowered to 3mm. absolute pressure. There is obtained 132.5 parts of product which isfound by infrared analysis to contain a carbonyl group. This product issoluble in oils and synthetic lubricants. Study of the product bynuclear magnetic resonance shows that the carbonyl is present chiefly asan aldehyde. There also appear to be some keto groups present.

Example 3 (a) A mixture of 60 parts of a polyolefin of a molecularweight of about 1200 derived from a fraction of polyolefins from propenethrough pentenes, 270 parts of ethanol, and 270 parts of n-hexane istreated with Ozone at -70 C. The ozone is supplied in a stream of oxygenat the rate of 1.45 millimoles per minute until an aliquot shows 0.05mole of peroxide has been formed.

(b) About one half part of platinum oxide is added to the above reactionmixture. While the mixture is kept at about 0 C., hydrogen is supplieduntil on titration of an aliquot with hydroxyamine there is a content of0.04 mole of carbonyl. The mixture is filtered and mixed withdi-2-ethylhexyl sebacate and heated to 100 C. under a pressure of 5 mm.absolute pressure. There was thus prepared a 20% solution of thecarbonylated polymer, which had a viscosity of 7.34 cs. at 210 F.

Example 4 (a) A mixture is prepared from 100 parts of a commercialpolybutene of a molecular weight of about 1200, 400 parts of n-heptane,and 30 parts of methanol. Temperature of the mixture is adjusted toabout 3 C. and ozone in oxygen is passed in at the rate of 1.46millimoles per minute for 50 minutes.

(b) The above solution is treated with two parts of a platinumhydrogenation catalyst held at 0 to 10 C., and reacted with .08 mole ofhydrogen.

The mixture is then filtered and solvent evaporated to give a residue of98 parts which contains 86% of the theoretical carbonyl groups which maybe introduced into this polymer.

For purposes of comparison a mixture of 60 parts of the polybutene usedin Example 4 and 160 parts of heptane is treated with ozone in air atthe rate of 1.45 millimoles of ozone per minute for 30 minutes. Thesolution is heated under reflux for 16 hours to decompose peroxides.Solvent is evaporated to give the product as a residue. By infraredanalysis it is found to contain carbonyl groups, but ony 53% of thetheoretical carbonyl groups are present.

Example 5 (a) A mixture is prepared from 600 parts of the polybuteneused just above, 800 parts of toluene and 320 parts of methanol. It iskept at about 5 C. and treated with ozone for 300 minutes at the rate of1.45 millimoles per minute.

(b) To the resulting solution is added 30 parts of a catalyst consistingof 5% palladium on carbon. Hydrogen is introduced at 55 C. while themixture is agitated. When the rate of addition of hydrogen slows up, thesolution is filtered and the product is obtained after the sovent isremoved by heating. The product is found to contain 1.46% of oxygen.Theory for one oxygen per unit of 1200 molecular weight is 1.33%. Theproduct is a viscous liquid.

Example 6 The procedures of Example 5 are repeated starting with amixture of 200 parts of a polybutene of a molecular weight of 2400, 320parts of hexane, and 120 parts of methanol. The same palladium catalystis used. The final product contains by analysis 0.67% of oxygen (theoryfor one oxygen per unit of 2400 molecular weight is 0.67% The product isa highly viscous liquid.

Example 7 The procedure of the above example is followed starting with1025 parts of a polybutene of a molecular weight of 4100, 1200 parts oftoluene, and 240 parts of methanol. Ozone at 1.45 millimoles per minuteis supplied for 158 minutes. Hydrogen is reacted at 25 to 30 C. with theaid of the palladium on carbon catalyst. The residue is found to contain0.31% of oxygen (theory 0.39%). The product is a viscous liquid.

Example 8 The above procedure is followed starting with a polybutene ofabout 330 molecular weight. After ozonolysis is carried out to about90%, the intermediate is treated with hydrogen in the presence ofpalladium catalyst to give a carbonyl-containing product. Hydroxylaminetitration shows a carbonyl content of 2.59 millimoles per gram ofproduct, an 86% conversion. This product is a liquid free of color. Itis soluble in esters and other oils.

Example 9 Into a solution of 120 parts of polypropene having a molecularweight of about 1200 in 450 ml. of n-heptane and ml. of methanol ispassed a stream of ozone in ozygen (69.5 mg. ozone/ per minute) for 55minutes while the solution is held at 0-5 C. The peroxidic products aredecomposed with hydrogen using 5 parts of 5% palladium on aluminacatalyst. The catalyst is removed and solvents distilled under vacuum toleave the product which has a carbonyl value of 0.632 millimole per gramas determined by hydroxylamine titration.

Example Into a solution of 50 parts of polyisobutene having a molecularweight of about 2500 in 300 ml. of 50% octanol-50% decanol is passed astream of ozone in ozygen (1.45 millimoles of ozone per minute) for 13minutes. The solution is then treated with hydrogen in the presence of 2parts of 1% palladium on alumina. The catalyst and solvents are removedto leave a viscous product whose infrared spectra shows a strongabsorption at 1718 cm? and which has a carbonyl value of 0.18 millimoleper gram as determined by hydroxylamine titration.

The carbonyl-containing aliphatic polymers prepared as above-describedare useful as lubricants themselves and as additives for lubricatingcompositions. They may be mixed with petroleum oils or syntheticlubricants and the resulting compositions may contain other additivessuch as stabilizers, anti-oxidants, pour-point depressors, corrosioninhibitors, dispersing agents, oiliness agents, antifoam agents,viscosity modifiers or anti-wear agents and combinations thereof.

In these lubricating compositions the carb0nyl-contain ing polymers ofthis invention serve to increase viscosity. They also supply dispersingactivity. The present polymers are employed in petroleum oils orsynthetic lubricants in any amounts being completely compatibletherewith. Particularly advantageous compositions are prepared by usingabout 0.1 to 50%, preferably 0.5 to 40%, by weight of acarbonyl-containing polymer of this invention.

A synthetic lubricant was prepared from 18 parts of acarbonyl-containing polymer of a molecular weight of about 620, 0.5 partof phenothiazine and 81.5 parts of bis(isodecyl) adipate. Thiscomposition has viscosities of 5.28 cs. at 210 F. and 25.70 cs. at 100F., corresponding to a viscosity index of 149.

Another composition was prepared from parts of the samecarbonyl-containing polymer used above, 0.5 part of phenothiazine, 0.75part of phenyl-u-naphthylamine, 1.3 parts of a copolymer from a mixtureof 40% butyl methacrylate and 60% lauryl-myristyl methacrylate and 82.55parts of bis(isodecyl) adipate. This composition has viscosities of 5.27cs. at 210 F. and 25.36 cs. at 100 F., giving a viscosity index of 151.These compositions are useful in turbo jet and turboprop engines.

Another lubricating composition is prepared from 10 parts of thecarbonyl-containing polymer from polybutene with a molecular weight ofabout 800, one part of phenothiazine, 0.03 part of sebacic acid andbis(isoctyl) adipate to make 100 parts. The viscosities of this mixtureare 4.17 cs. at 210 F. and 16.37 cs. at 100 F., corresponding to aviscosity index of 181.

A lubricating composition is prepared from 10 parts of thecarbonyl-containing derivative of a polybutene of a molecular weight of2,400, one part of 4,4'-methylenebis-(2,4-di-tert-butylphenol), and 89parts of a 170 neutral oil prepared from mid-content stock with solventextraction. This composition has viscosities of 10.60 cs. at 210 F. and83.23 cs. at 100 F., corresponding to a viscosity index of 117.

Lubricating compositions are prepared by blending (1) 20 parts of apolybutene of a molecular weight of 1200 with 80 parts ofdi-Z-ethylhexyl sebacate containing 0.025% of free sebacic acid, (2) 20parts of the saturated polymer obtained from the same polybutene byhydrogenation and 80 parts of the same preparation of di- 2-ethylhexylsebacate and (3) 20 parts of the carbonylcontaining polymer derived fromthe above polybutene by the method defined above and 80 parts of thesame preparation of di-2-ethy1hexyl sebacate.

The lower pour point (determined by the A.S.T.M. method) for blend 3demonstrates the greater compatibility of the carbonyl-containingaliphatic hydrocarbon polymers and one of the substantial advantagesthereof.

A commercial polybutene of molecular weight of about 440 is ozonizedaccording to Example 5. One portion of the ozonized solution is treatedaccording to Example 5(b) and a second portion according to Example 11.Both are stripped of solvent and tested for their ability to dissolveasphaltene sludge.

One half ml. of chloroform containing 10 mg. of asphaltene sludge isadded to 5 ml. of each of the carbonylated polybutene preparations in atest tube. The chloroform is removed by heating in an oven. The sludgeprecipitates from the polybutene solution but not from the carbonylatedpolybutene liquids. Incremental amounts of sludge are added until aprecipitate forms. A summary of these data is below.

Polybutene (molecular weight about 440) Treatment with ozone o e (0 (9Post ozone treatment None Carbonyl value (hydroxylamine method Nil 1.57 1. 30

rnillimoles per gram.

Oentistokes at 210 F 10. 71 12. 35 16. 30

Mg. sludge/5 ml. fluid 10 120 1 As in Exam. 5. 2 As in Exam. 5b. 3 As inExam. 11.

We claim:

1. A lubricating composition comprising an oily dialkyl ester of .adicarboxylic acid having dissolved therein a pour point reducing amountof an oil-soluble hydrocarbon polymer having a molecular weight of about300 to about 5000 and bearing a carbonyl group, said polymer being madeby reacting an olefinic polymer which is derived from an olefincontaining 3 to 12 carbon atoms and which has a molecular weight ofabout 300 to 5000 with ozone until an ozonolysis product is formed andreducing the resulting ozonolysis product until a carbonyl group isformed thereon.

2. A lubricating composition according to claim 1 wherein saidhydrocarbon polymer is a polybutene poly- =mer having a molecular weightof about 300 to about 5 000 and bearing a carbonyl group.

3. A lubricating composition according to claim 1 wherein said olefincontains 3 to 5 carbon atoms.

References Cited UNITED STATES PATENTS 2,250,468 7/1941 Cockerville25255 X 2,251,550 8/1941 Lieber 25252 X 2,334,996 11/1943 Davis 252552,824,131 2/1953 DiNardo 25255 2,992,987 7/1961 Fields 25256 DANIEL E.WYMAN, Primary Examiner.

W. H. CANNON, Assistant Examiner.

US. Cl. X.R. 25255, 56; 260452

